As an alternative to using an additional grep -v grep you can use a simple regular expression in the search pattern (first letter is something out of the single letter list ;-)) to drop the grep command itself.

Within /proc and /sys there are a lot of subdirectories, which carry pseudofiles with only one value as content. Instead of cat-ing all single files (which takes quite a time) or do a "cat *" (which makes it hard to find the filename/content relation), just grep recursively for . or use "grep . /blabla/*" (star instead of -r flag).

For better readability you might also want to pipe the output to "column -t -s : ".

Get the name of the parent command. This might be helpful, if you need to react on that information. E. g. a script called directly via ssh has got sshd as parent, manually invoked the parent process will probably be bash

If you are doing some tests which require reboots (e. g. startup skripts, kernel module parameters, ...), this is very time intensive, if you have got a hardware with a long pre-boot phase due to hardware checks.

At this time, kexec can help, which only restarts the kernel with all related stuff.

First the kernel to be started is loaded, then kexec -e jumps up to start it.

Is as hard as a reboot -f, but several times faster (e. g. 1 Minute instead of 12 on some servers here).

You got some results in two variables within your shell script and would like to find the differences? Changes in process lists, reworked file contents, ... . No need to write to temporary files. You can use all the diff parameters you'll need. Maybe anything like $ grep "^>"